一个用JAVA开拓的会话密钥措施

/*

运行本措施你需要下载JCE，Bouncy Castle的JCE with Provider and Lightweight API

网址是 http://www.bouncycastle.org

设置如下：

在WINDOWS中，你需要把下载的bcprov-jdk14-119.jar文件拷贝到两个处所：

一个在你安装的JDK目次中，好比说我的是C:\j2sdk1.4.0-rc\jre\lib\ext

另一个在你的JDK运行情况中，我的是在

C:\Program Files\Java\j2re1.4.0-rc\lib\ext；

别的还要在对两个java.security举办修改：

我的在 C:\j2sdk1.4.0-rc\jre\lib\security\java.security；

C:\Program Files\Java\j2re1.4.0-rc\lib\security\java.security;

在java.security中插手 security.provider.6=org.bouncycastle.jce.provider.BouncyCastleProvider

假如一切顺利，你就可以运行本措施了。

该措施具有对你的文件加解密成果。需要你指定的数据，措施中已给了接口。

好比说你指定了要加密的文件名"4.txt",加密后的文件存放位置"6.txt",

尚有口令password如"liufeng"后，运行该措施，那么"6.txt" 中将是"4.txt"的密文。

留意口令是解密的钥匙，不要健忘。

其他解密进程本身参考。

本措施操作会话密钥加密，提供许多接口。假如你项目中需要加密进程，可以稍加改造为你所用

*/

import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
import java.util.*;
public class FileEncryptorRSA {
private static final int ITERATIONS=1000;//计较次数，在加盐顶用到
private static byte[] publicKeyBytes;//公钥
private static byte[] privateKeyBytes;//私钥
private static String SessionKey;//会话密钥
public static String ENCRYPT_PRIVATEKEY_FILE="1.txt";//该文件安排加密的私钥
private static String TEXT_FILE="4.txt";//要加密的文件
private static String ENCRPTOR_TEXT_FILE="5.txt";//被加密后的文件
private static String DENCRYPTOR_TEXT_FILE="6.txt";//解密后的文件
private static String password="liufeng";//口令用于加密私钥
public void setTEXT_FILE(String fileName){
TEXT_FILE=fileName;
}
public void setENCRYPT_PRIVATEKEY_FILE(String fileName){
ENCRYPT_PRIVATEKEY_FILE=fileName;
}
public String getENCRYPT_PRIVATEKEY_FILE(){
return ENCRYPT_PRIVATEKEY_FILE;
}
public void setENCRPTOR_TEXT_FILE(String fileName){
ENCRPTOR_TEXT_FILE=fileName;
}
public String getENCRPTOR_TEXT_FILE(){
return ENCRPTOR_TEXT_FILE;
}
public void setDENCRYPTOR_TEXT_FILE(String fileName){
DENCRYPTOR_TEXT_FILE=fileName;
}
public String getDENCRYPTOR_TEXT_FILE(){
return DENCRYPTOR_TEXT_FILE;
}
public void setPassword(String password){
this.password=password;
}
//create a RSA secretKey
public static void createKey()throws Exception{
KeyPairGenerator keyPairGenerator=KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024);
KeyPair keyPair=keyPairGenerator.genKeyPair();
//获得公钥的字节数组
publicKeyBytes=keyPair.getPublic().getEncoded();
//获得私钥
byte[] privateKeyBytes=keyPair.getPrivate().getEncoded();
byte[] encrytedPrivatekey=passwordEncrypt(password.toCharArray(),privateKeyBytes);
FileOutputStream fos=new FileOutputStream(ENCRYPT_PRIVATEKEY_FILE);
fos.write(encrytedPrivatekey);
fos.close();
}
//通过给的口令加密私钥
private static byte[] passwordEncrypt(char[] password,byte[] privateKeyBytes)
throws Exception{
//create 8 byte salt
byte[] salt=new byte[8];
Random random=new Random();
random.nextBytes(salt);
//create a PBE key and cipher
PBEKeySpec keySpec=new PBEKeySpec(password);
SecretKeyFactory keyFactory=SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");
SecretKey key=keyFactory.generateSecret(keySpec);
PBEParameterSpec paramSpec=new PBEParameterSpec(salt,ITERATIONS);
Cipher cipher=Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
cipher.init(Cipher.ENCRYPT_MODE,key,paramSpec);
//Encrypt the byte[]
byte[] cipherPriKey=cipher.doFinal(privateKeyBytes);
//write out salt ,and then the cipherPriKey
ByteArrayOutputStream baos=new ByteArrayOutputStream();
baos.write(salt);
baos.write(cipherPriKey);
return baos.toByteArray();
}
//用会话密钥加密给定的文件，然后用公钥加密会话密钥，并存入文件中
//最后加密后的文件由密钥长度+已加密的密钥（会话密钥）+密文
public static void encrypt()throws Exception{
//转换成RSA密钥
X509EncodedKeySpec keySpec=new X509EncodedKeySpec(publicKeyBytes);
KeyFactory keyFactory=KeyFactory.getInstance("RSA");
PublicKey publickey=keyFactory.generatePublic(keySpec);
//打开存贮密文的文件
DataOutputStream output=new DataOutputStream(new FileOutputStream(ENCRPTOR_TEXT_FILE));
//建设RSA的CIpher
Cipher rsaCipher=Cipher.getInstance("RSA/ECB/PKCS1Padding");
rsaCipher.init(Cipher.ENCRYPT_MODE,publickey);
//建设会话密钥(Rijndael)
KeyGenerator rijndaelKeyGenerator=KeyGenerator.getInstance("Rijndael");
rijndaelKeyGenerator.init(256);
Key rijndaelKey=rijndaelKeyGenerator.generateKey();
//公钥加密会话密钥
byte[] encodedKeyBytes=rsaCipher.doFinal(rijndaelKey.getEncoded());
output.writeInt(encodedKeyBytes.length);
output.write(encodedKeyBytes);
//发生IV向量
SecureRandom random=new SecureRandom();
byte[] iv=new byte[16];
random.nextBytes(iv);
output.write(iv);
//加密正文
IvParameterSpec spec=new IvParameterSpec(iv);
Cipher symmetricCipher=Cipher.getInstance("Rijndael/CBC/PKCS5Padding");
symmetricCipher.init(Cipher.ENCRYPT_MODE,rijndaelKey,spec);
CipherOutputStream cos=new CipherOutputStream(output,symmetricCipher);
FileInputStream input=new FileInputStream(TEXT_FILE);
int theByte=0;
while((theByte=input.read())!=-1){
cos.write(theByte);
}
input.close();
cos.close();
return;
}
//获得私钥
private static byte[] passwordDecrypt(char[] password,byte[] ciphertext)
throws Exception{
byte[] salt=new byte[8];
ByteArrayInputStream bais=new ByteArrayInputStream(ciphertext);
bais.read(salt,0,8);
byte[] remainingCiphertext=new byte[ciphertext.length-8];
bais.read(remainingCiphertext,0,ciphertext.length-8);
PBEKeySpec keySpec=new PBEKeySpec(password);
SecretKeyFactory keyFactory=SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");
SecretKey key=keyFactory.generateSecret(keySpec);
PBEParameterSpec paramSpec=new PBEParameterSpec(salt,ITERATIONS);
Cipher cipher=Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
cipher.init(Cipher.DECRYPT_MODE,key,paramSpec);
return cipher.doFinal(remainingCiphertext);
}
//解密加密的文件
public static void decrypt()
throws Exception{
FileInputStream fis=new FileInputStream(ENCRYPT_PRIVATEKEY_FILE);
ByteArrayOutputStream baos=new ByteArrayOutputStream();
int theByte=0;
while((theByte=fis.read())!=-1){
baos.write(theByte);
}
fis.close();
//获得被加密的私钥
byte[] keyBytes=baos.toByteArray();
baos.close();
//获得私钥
byte[] sKey=passwordDecrypt(password.toCharArray(),keyBytes);
//发生RSA私钥
PKCS8EncodedKeySpec keySpec=new PKCS8EncodedKeySpec(sKey);
KeyFactory keyFactory=KeyFactory.getInstance("RSA");
PrivateKey privateKey=keyFactory.generatePrivate(keySpec);
Cipher rsaCipher=Cipher.getInstance("RSA/ECB/PKCS1Padding");
DataInputStream dis=new DataInputStream(new FileInputStream(ENCRPTOR_TEXT_FILE));
//读密文中暗码长度和暗码
byte[] encryptedKeyBytes=new byte[dis.readInt()];
dis.readFully(encryptedKeyBytes);
rsaCipher.init(Cipher.DECRYPT_MODE,privateKey);
byte[] rijdaelKeyBytes=rsaCipher.doFinal(encryptedKeyBytes);
//获得会话密钥
SecretKey rijndaelKey=new SecretKeySpec(rijdaelKeyBytes,"Rijndael");
byte[] iv=new byte[16];
dis.read(iv);
IvParameterSpec spec=new IvParameterSpec(iv);
//用会话密钥解密正文
Cipher cipher=Cipher.getInstance("Rijndael/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE,rijndaelKey,spec);
CipherInputStream cis=new CipherInputStream(dis,cipher);
FileOutputStream fos=new FileOutputStream(DENCRYPTOR_TEXT_FILE);
theByte=0;
while((theByte=cis.read())!=-1){
fos.write(theByte);
}
cis.close();
fos.close();
return;
}
public static void main(String[] args)throws Exception{
createKey();
encrypt();
decrypt();
}
}